Cylinder for printing presses



May 8, 1945.

R. P. WILLARD CYLINDER FOR PRINTING PRESSES Filed Dec. 26 1941 PatentedMay 8, 1945 "um rap STATES PATENT OFFICE Moore Business Form Delaware 5,Inc., a corporation of Application December 26, 1941, Serial No. 424,481

8 Claim.

This invention relates to improvements in printing presses, and moreparticularly to an improved attaching means for attaching printingplates in operative position on the printing cylinders or othersupporting surfaces of the printing presses.

It is a general object of the invention to provide an improved attachingmeans for attaching printing. plates in operative position uponsupporting surfaces thereof, such as rotary printing l0 cylinders. Theimproved attachment embodies a simple and inexpensive structure thatmaterially reduces the time and labor required for preparing theprinting plate and applying it in operative position on the supportingsurface of the print- 1 ing press such, for example, as a rotarycylinder thereof.

A further object of the invention is to provide an improved attachingmeans for attaching printing plates in operative position upon asupporting cylinder in such a manner as to avoid unbalancing of thecylinder and thus permitting rotation at high speeds without causingobjectional vibration, thus materially improving the quality of theprinting and at the same time increasing the speed of production of theprinted matter.

Still another object of the invention is to provide an improvedattachment for attaching printing plates in operative position andembodying an improved automatic self-adjusting attachment, automaticallyattaching the trailing or tail end of the plate in successive adjustedpositions such, for example, as in cases where the plate in actualprinting operation becomes slightly elongated due to slight stretching,to seating of the leading end attachment in finnly seated position, andprobably also to other causes.

A further object of the invention is to provide tioned whereby theprinting plate can occupy substantially the entire length of thesupporting surface such, for example, as substantially the entirecircumference of a printing cylinder, internal attachment of thetrailing end of the plate with consequent recessing of the cylinderbeing sub stantially avoided.

According to another and more specific feature of the invention, animproved plate attaching arrangement is provided which is positionedsubstantially in the line of the plate supporting sur face, for example,substantially in the cylindrical surface of a rotary cylinder, thusavoiding the necessity of bending or offsetting the printing plate andfacilitating the automatic reattachment of the plate followinglongitudinal adjustments thereof due to stretching or seating thereofmore firmly into operative position, and also due to other causes.

Other objects and advantages of the invention will be in part pointedout in the following detailed disclosure of an illustrative butpreferred embodiment of the invention, and will be in part obvious asthe disclosure proceeds.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts, which will beexemplified in the construction hereinafter set forth and the scope ofthe application of which will be indicated in the claims.

For a more comprehensive disclosure of the nature, objects andadvantages of the invention, reference is had to the following detaileddescription of the preferred illustrative embodiment and to theaccompanying drawing, in which:

Fig. 1 is a fragmentary perspective view of a rotary printing cylinderembodying the improved attaching means for attaching a, printing platein operative position thereon.

Fig. 2 is an enlarged fragmentary transverse sectional view of thecylinder of Fig. 1, showing the improved plate attaching means ingreater detail.

Fig. 3 is a top plan view of one form of printing plate that may beutilized in connection with the invention; and

' Fig. 4 is a side elevation of the printing plate of Fig. 3.

, Referring now to the drawing for a detailed description of theillustrative'embodiment there shown, the printing cylinder 5 may beconstructed in well known manner of metal or similar materialand isprovided with journals, one of which is shown at 6, for rotatablymounting the cylinder an improved attachment of the character men- 40 ina printing press of known construction. This printing cylinder, asunderstood by those skilled in the art, will be mounted for cooperationwith an impression or blanket cylinder and other printing presselements. The cylinder may be made of any desired length and diameterfor accommodation of printing plates of appropriate size for productionof the required printed matter, and may be made of sufficiently smalldiameter so that a plate six or eight inches in length, or even less,will extend substantially all the way around the cylinder.

This printing cylinder 5 is provided with a longitudinally extendingslot 1 cut in the body thereof and preferably extending for the lengthof the cylinder as shown. This slot is small in transverse diameter soas to receive snugly an attaching flange at one of the terminals of theprinting plate and will therefore vary in thickness in accordance withthe particular printing plates employed. For a purpose later described,it will to accommodate the particular printing plates being used. Thisshallow groove 8 for clearness is shown somewhat exaggerated in depth inthe drawing, and ordinarily it will be quite shallow, a depth of about.006 to .010 of an inch having been found to be satisfactory forordinary purposes. Preferably, .as shown, the shallow groove 8 mergeswith the inclined attaching slot 1. The bottom of the shallow groove maybe cylindrical concentric with the surface of the cylinder 5, or it maybe fiat and substantially perpendicular at its transverse center to thecylinder radius. While, for illustrative purposes, a cylinder providedwith a. single slot 1 and a single groove 8 has been shown, it will beunderstood that additional slots and grooves arranged as disclosed maybe employed in cases where it is desired to attach more than oneprinting plate to the cylindrical surface.

Seated in the shallow groove 8 is an adhesive attaching device 9 shownin tlie form of an dhesive tape having adhesive material I both at theupper and the lower surfaces thereof. The adhesive at the lowersurfaceattaches the tape in position in the shallow groove 8 while theadhesive at the upper surface is arranged for contacting with the undersurface of the rear or following edge portion of the printing plate forattaching the same in operative position. For this purpose the shallowgroove 8 and the attaching tape 9 are proportioned so that the upperadhesive attaching surface lies substantially in line with thecylindrical supporting surface of the cylinder. In other words, theupper adhesive attaching surface provides a substantially cylindricalextension or continuation of the cylindrical supporting surface of thecylinder. In this manner there is no interruption to the cylindricalsupporting surface at the attaching edge of the printing plate, thusproviding a true cylindrical outer surface for the printing plate atthis attached edge portion thereof.

As mentioned above, it is desirable in some cases to construct thebottom or supporting surface of the shallow groove 8 substantiallycylindrical and concentric with the cylindrical plate supporting surfaceof the cylinder 5. Thus, it is referred that the bottom of the groove becylindrical in cases where the attching tape 9 is of considerable width,say about /2 or more. This maintains the upper adhesive surface of thetape substantially cylindrical in cases where the adhesive attachingtape is of uniform thickness throughout. A similar result can beobtained by making the bottom surface of the groove 8 substantially fiatand constructing the attaching tape of varying thickness with acylindrical upper surface and flat lower surface so as to present theupper adhesive surface l9 thereof substantially cylindrical to form acylindrical continuation of the supporting surface of the cylinder. Incases where the attaching tape 9 is quite narrow, from say to about thbottom of the groove 8 can be made flat and the tape of uniformthickness, since in this case the deviation from a true cylindricalsurface of the upper adhesive supporting surface would be negligible.The tape widths mentioned are only approximate and would be differentfor cylinders of varying circumference, those given being for cylindersabout 12" and less in circumference.

While the particular specific character of the adhesive attaching devicemay vary, an adhesive tape of textile fabric, tough paper, cellulosicsheet .material, or other flexible material has been found to besatisfactory. The adhesive I0 is preferably of th non-drying type andmay embody rubber or latex such as the well known friction tape employedin electrical work. A very satisfactory adhesive for this purpose is thenondrying, pressure sensitive, cold sealing adhesive used in the productknown as Scotch tape such as fully described in United States LettersPgtgnt No. 2,177,627, Drew, dated October 31, l 3

One type of printing plate such as may be used in connection with theimproved attaching device is shown in Figs. 3 and 4 of the'drawing, butother types of plates such as zinc lithographic plates may be utilized.As shown, this printing plate I l is in the form of a flexible sheet ofmetal, or cellulosic material such as any of the well known plasticmaterials, and is provided at its forward or leading edge with adownwardly inclined attaching flange l2. This attaching flange I2 isadapted to be received within the inclined attaching slot 1 and isinclined at an acute angle to the plate corresponding to the inclinationof the slot 7 to the cylinder surface. In the form shown, printingplates l3 of rubber or similar material are adhesively attached to theupper surface of th base or supporting plate H. The upper surfaces ofthese rubber plates are formed with the data that is to be printed uponthe paper or other material as well known in the art. A lithographicplate may be substituted for the rubber plates in which case the baseplate ll would be made of appropriate material such as paper orzincjtheupper surface of which is provided with the data or design to beprinted. The end portion of the plate H opposite to the attaching flangeI2 is a straight continuation of the body of the plate and it isunnecessary to modify it in any way in order that it may cooperate withthe improved attaching device for attaching the trailing end of theplate in operative position upon the cylinder.

When the cylinder has been prepared, as above described, with theadhesive attachment 9 in place, theprinting plate ll having theattaching flange I! can be quickly and easily placed in operativeposition upon the cylinder. It is only necessary to enter theattachingflange 12 in the inclined slot 1 and extend the plate upon thesupporting surface of the cylinder until the trailing end portionthereof comes into overlapping relation with the adhesive attachment.When the plate has thus been positioned in close contact with theperiphery of the cylinder, the trailing edge portion is pressed intofirm contact with the upper adhesive surface ll] of the adhesiveattachment. The pressure exerted along the edge portion of-the plateover the adhesive is sufficient to cause the plate to adhere firmly inposition, whereupon the cylinder is ready to be started for the printingoperation.

It will be noted that the inclined flange l2 engaging in the inclinedslot I provides a hooklike attaching means for the forward end of theprinting plate ll. When operation of the cylinder is started there maybe some slight longitudinal adjustment or elongation of the plate II onthe periphery of the cylinder due partly to the firmer seating of theflange in the inclined slot, partly to slight elongation or stretchingof the plate, and partly to other causes. When this elongation occurs itwill be seen that the adhe sive attachment of the trailing end of theplate is automatically adjusting. As the plate is elongated slightly inth manner suggested, the

' adhesive attachment will be released as operative rotation of thecylinder continues, and the plate will be automatically reattached inits adjusted position by the adhesive attachment due to continuedrotation of the cylinder and the pressure exterted at the attachedtrailing edge by the impression cylinder or other cooperating element.In this manner the printing plate is maintained firmly supported in itsvarious adjusted positions upon the cylindrical surface. tion it will benoted that the plate is free and unattached from the cylindrical surfaceof the cylinder except at its forward and rearward extremities so thatthe adjustments mentioned can be accomplished, the slight loosenessduring elongation being freely transmitted along the plate to theadhesive attachment.

It will be noticed that there is very little mutilation or cutting awayof the cylinder 5 for adapting it for this improved plate attachingdevice. Consequently'there is little or no unbalancing of the cylinderand it can be operated a high speeds without causing any detrimentalvibration such as might interfere with the quality of the printing. Thisis of particular importance where cylinders of small diameter are used,since they can be run at high speed so as to maintain large production.Since the attaching device requires very little circumferential spaceupon the cylinder, and the surface of the plate directly at the adhesiveattachment can be utilized for printing, it will be noted that theprinting surface of the printing plate can occupy substantially theentire periphery or nearly 360 of the cylinder thus resulting in asaving in material and speeding up of production.

Since certain changes may be made in the above construction anddifferent embodiments of the invention could be made without departingfrom the scope thereof, it is intended that all matter contained in theabove description or shown in the accompanying drawing shall beinterpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. ,In a printing apparatus, in combination, a support having asupporting surface, a printing plate supported in operative position onsaid surface, a non-drying, pressure sensitive adhesive attaching deviceattaching one terminal portion of said plate in operative position uponIn this connecsaid supporting surface, and a second attaching device forsaid printing plate spaced longitudinally of the latter from saidadhesive attaching a device and firmly attaching the printing plateagainst longitudinal movement, said printing.

plate being supported by said supporting surface but free from directattachment thereto intermediate said adhesive attaching device and saidsecond attaching device, whereby said adhesive attaching devicefunctions as an adjustable attachment for taking up slack or loosenessof the printing plate.

2. In a printing apparatus, in combination, a support having a,supporting surface, a printing plate supported in operative position. onsaid surface, and an adhesive attaching device attaching one terminalportion of said plate in operative position upon saidsupporting surface,said adhesive attaching device including a nondrying pressure sensitiveadhesive attaching surface positioned substantially in the line-of saidsupporting surface and substantially forming a continuation thereof,saidattaching device forming a support to support the attached terminalportion of the printing plate in operative printing position with itsouter surface substantially forming an uninterrupted continuation of themain surface of the plate, said printing plate being supported by saidsupporting surface but being free from direct attachment thereto for aconsiderable distance along said supporting surface from said adhesiveattaching surface which functions as an adjustable attachment for takingup slack or looseness of the printing plate.

3. In a printing apparatus, in combination, a support having asupporting surface and having a slot inclined to said surface, aprinting plate supported in operative position on said surface andhaving at an edge portion an attaching flange extending into said slot,and an adhesive attachment attaching the opposite edge portion of saidprinting plate in position upon said support, said adhesive attachingdevice including a non-drying, pressure sensitive adhesive attachingsurface positioned substantially in the line of said supporting surfaceand substantially forming a continuation thereof, and said printingplate being free from direct attachment with said supporting surfaceintermediate said attaching flange and said adhesive attaching surfacewhereby said adhesive attaching device is adjustable for taking up slackor looseness of the printing plate, said adhesive attachment forming asupport for supporting said opposite edge portion substantially in theline of said printing plate as an uninterrupted continuation thereof.

4. In a printing apparatus, in combination, a support having acylindrical supporting surface, a printing plate supported in operativeposition on said supporting surface, means for attaching ,with saidshallow groove, a printing plate supported in operative position on saidsupporting surface, an attaching flange at the leading edge portion ofsaid plate extending into said slot to provide an attachment for theplate, and a nondrying, pressure sensitive ahesive attachment in saidshallow groove for attaching the rear or following edge portion of saidprinting plate in' operative position.

6. In a printing apparatus, in combination, a

rotary support having a cylindrical supporting surface for supportingone or more printing I plates in operative position and having a shallowgroove opening outwardly through said surface, said rotary support alsohaving a narrow slot rearwardly inclined to said supporting surface andmerging with said shallow groove, and an adhesive attachment in saidshallow groove for attaching the rear or following edge portion of aprinting plate in operative position, said adhesive attachmentsupporting said rear edge portion substantially as an uninterruptedcylindrical continuation of said plate and having a non-drying, pressuresensitive adhesive surface i positioned substantially in the line ofsaid cylindrical surface and providing an automatically adjustingattachment for the plate.

- 7. In a printing apparatus in combination, a rotary support having acylindrical supporting surface and having a shallow groove openingoutwardly through said surface, said rotary support also having a narrowslot cut in the body thereof. a printing plate supported in operativeposition on said supporting surface, an attaching flange at the leadingedge portion of said plate extending into said slot to provide anattachment for the plate, and an adhesive attachment in said shallowgroove for attaching the rear or following edge portion of said printingplate in operative position. said adhesive attachment including anadhesive tape having nondrying adhesive upper and lower attachingsurfaces.

8. In a printing apparatus, in combination, a support having asupporting surface, a printing plate supported in operative position onsaid supporting surface, means for attaching the leading terminal ofsaid plate in operative position on said supporting surface, and anautomatically adjusting attachment for attaching the trailing terminalof said plate in operative position on said support, said automaticallyadjusting attachment being substantially immovable in a direction towardor away from said supported leading terminal of said printing plate and.forming in all of its different adjustments a support ing surface forsaid printing plate which is substantiaily an uninterrupted continuationof said first mentioned supporting surface, the said supporting surfaceof said adjusting attachment being positioned substantially in line withsaid nrst mentioned supporting surface so as to support said attachedtrailing terminal in any adjustment thereof substantially in the line ofsaid printing plate whereby a continuous uninterrupted printing surfacein operative printing position is provided extending from said firstmentioned supporting surface to and over said supporting surface of saidadjusting attachment. ROBERT P. WILLARD.

